In open-pit mining large haul trucks and other vehicles are used to transport the ore from the bottom of the pit to the surface. A low incline haulage road is employed on the pit wall to enable the vehicles to travel up out and down into the pit. An important safety feature of the haulage road is the provision of a safety bund or rock berm to prevent vehicles from accidentally leaving the road, either due to driver inattention, poor visibility or brake failure. Such rock bunds are also employed along pit ramp edges. Typically a safety bund is employed that consists of dirt and rock piled along the edge of the haulage road or pit ramp. Government regulations typically require the safety bund to be at least half the height of the wheels of the largest mining machine on-site.
There are several disadvantages of rock bunds. There is always the danger that a fully-loaded runaway truck will simply ride up and over, or crash through, the rock bund when travelling at high speed. This is because the incline of the sides of the rock bund, as defined by the angle of repose of the dirt and rock used to make it, may be relatively shallow. There is a further disadvantage due to the fact that the rock bund occupies a substantial area along the edge of the road or ramp, which reduces the width of the road or ramp and/or increases the total width of the land that has to be set aside for the road or ramp. This represents ‘wasted’ space, which is economically valuable; if some of this wastage can be eliminated by reducing the footprint of the safety bund it will result in significant savings.
The present invention was developed with a view to providing an edge protection safety bund system that improves the effectiveness of a rock bund in an open-pit mine. Although the following description of the edge protection safety bund system will be given primarily with reference to its application in an open-pit mine, it will be apparent that it may also have wider applications.
References to prior art in this specification are provided for illustrative purposes only and are not to be taken as an admission that such prior art is part of the common general knowledge in Australia or elsewhere.